x__heavenly__x Posted July 14, 2004 Share Posted July 14, 2004 We have seen that out kitchen fridge magnets stay attached even though gravity is acting on it (and other forces too). I dont get it that how come there is infinite energy in it to defy gravity?....wats the reaction of the action?......some explaination my friends gave : : 1. The total energy is reducing by time(takes millions of years)....I dont like this theory. 2. Maybe everything is happening inside the magnet. The minute circular loops of current which sustains the magnetism is constant...like the stability of a proton electron system!? Thank you ! Link to comment Share on other sites More sharing options...
timo Posted July 14, 2004 Share Posted July 14, 2004 you don´t need energy to cancel out a force (gravitational force octing on the magnet in this case). You need force. You examle with the magnet is essentially the same as with the cup of coffee standing on my table in front of me: If doesn´t fall down eben though gravity works on it. That doesn´t mean the table puts infinite energy in it over time. It simly means the force of the table acting back on my cup of coffee cancels out the force of gravity. The reaction would be: - Force Fg tries to pull the magnet down. - Frictional force Ff caused by the magnet being pressed against the kitchen fridge (due to magnetic attraction) cancels out the force of gravity: Ff = -Fg. - Total force working on the magnet: F = Ff + Fg = 0. - Force is change of momentum (basically speed - I dunno about your lvl of physics) over time. Since F=0 the speed of the magnet doesn´t change over time => magnet remains where it is. - Note that energy never appeared in above. To sum it up: Forces only have an effect on energy when applied over a distance. Since there´s no change of poisitions involved in a static setup energy becomes irrelevant (I´m not 100% sure if that statement is correct for all cases but it applies for your question and I wanted to keep my answer as simple as possible). Link to comment Share on other sites More sharing options...
YT2095 Posted July 15, 2004 Share Posted July 15, 2004 magnetism is also a far stronger nuclear force than gravity as well. gravity is quite weak by comparison, hence a magnet will pick up a paper clip perpendicular to the force of gravity. neither forces are sources of energy though, infinate or otherwise Link to comment Share on other sites More sharing options...
swansont Posted July 15, 2004 Share Posted July 15, 2004 magnetism is also a far stronger nuclear force than gravity as well. This is worded a tad awkwardly, since the electromagnetic force and nuclear forces are distinct forces under the circumstances under which we are discussing. (The weak nuclear force does unify with the electromagneic force to become the electroweak force, but this happens at thermal energies above 100 GeV. The strong nuclear force has not yet been unified) Link to comment Share on other sites More sharing options...
ydoaPs Posted July 15, 2004 Share Posted July 15, 2004 Gravity is the weakest of the forces. Link to comment Share on other sites More sharing options...
JaKiri Posted July 16, 2004 Share Posted July 16, 2004 Gravity is the weakest of the forces. Not at distance :q: Link to comment Share on other sites More sharing options...
Duke Posted July 16, 2004 Share Posted July 16, 2004 Could a large amount of gravity ever be stronger than electro magnetism? I.e the force that stops gravity pulling my ass through my chair Link to comment Share on other sites More sharing options...
ydoaPs Posted July 16, 2004 Share Posted July 16, 2004 Thats a good question. It would be fun, but it might really suck. Link to comment Share on other sites More sharing options...
JaKiri Posted July 16, 2004 Share Posted July 16, 2004 Could a large amount of gravity ever be stronger than electro magnetism? I.e the force that stops gravity pulling my ass through my chair Forces approach infinity as seperation approaches 0, so no, you could never overcome the electrostatic repulsion by just applying a larger and larger force. Link to comment Share on other sites More sharing options...
[Tycho?] Posted July 18, 2004 Share Posted July 18, 2004 And "permanent" magnets are not permanent. It takes a long time, but they will lose their magnetism eventually. Link to comment Share on other sites More sharing options...
Skoteinos Posted August 11, 2004 Share Posted August 11, 2004 Not at distance :q: A planet-sized magnet (magnetized iron, neodyminium, nickel, whatever) will easily have more force than a planet-sized non-magnet (aka earth) , ( Not including the gravitational effects of a planet-sized magnet ) Link to comment Share on other sites More sharing options...
swansont Posted August 12, 2004 Share Posted August 12, 2004 A planet-sized magnet (magnetized iron' date=' neodyminium, nickel, whatever) will easily have more force than a planet-sized non-magnet (aka earth) , ( Not including the gravitational effects of a planet-sized magnet )[/quote'] The earth is a non-magnet? Then how do compasses work? Link to comment Share on other sites More sharing options...
Severian Posted August 12, 2004 Share Posted August 12, 2004 I feel the urge to clear up a falacy here (I'm being pedantic). The electromagnetic force and the weak nuclear force have not been unified. They have only been decribed by a theory which inextricably links them (in fact the photon is a mixture of the U(1) gauge boson and one of the SU(2) gauge bosons). But they still have separate coupling constants and are still spearate forces (unlike the unification of electricity and magnetism into different manifestations of one force - elecrtomagnetism). Link to comment Share on other sites More sharing options...
5614 Posted August 12, 2004 Share Posted August 12, 2004 A planet-sized magnet (magnetized iron' date=' neodyminium, nickel, whatever) will easily have more force than a planet-sized non-magnet (aka earth) , ( Not including the gravitational effects of a planet-sized magnet )[/quote'] as swansont says, YES, the eath is a magnet! gravity is a relatively weak force! magnets do loose their magnetism, but only after millions of years, they are classified as an infinite source, as 'officially' is the sun, however, as we know, eventualy, they will both ware out! and loose their magnetism, [and the sun its, well everything! it turns into a red giant.] Link to comment Share on other sites More sharing options...
Rootje Posted August 27, 2004 Share Posted August 27, 2004 Could a large amount of gravity ever be stronger than electro magnetism? I.e the force that stops gravity pulling my ass through my chair Yes, accoding to Hawkings it can. If you just take enough particles, the total amount of gravity they exert on one another becomes too great for the elektromagnetic forces to repell them, thus letting atoms collaps under the weight of all other atoms, fusing electrons and protons to create neutrons. You just made a neutron-star. Now it's the strong nuclear force creating resistance to further collapse, but just keep on adding mass and eventually even that force is outstronged by gravity, making further collapse possible. Now you made a black hole. Link to comment Share on other sites More sharing options...
slickinfinit Posted November 6, 2004 Share Posted November 6, 2004 Yes' date=' accoding to Hawkings it can. If you just take enough particles, the total amount of gravity they exert on one another becomes too great for the elektromagnetic forces to repell them, thus letting atoms collaps under the weight of all other atoms, fusing electrons and protons to create neutrons. You just made a neutron-star. Now it's the strong nuclear force creating resistance to further collapse, but just keep on adding mass and eventually even that force is outstronged by gravity, making further collapse possible. Now you made a black hole.[/quote'] I completely agree the more matter the more gravity very simple even I understand lol Link to comment Share on other sites More sharing options...
swansont Posted November 6, 2004 Share Posted November 6, 2004 Yes' date=' accoding to Hawkings it can. If you just take enough particles, the total amount of gravity they exert on one another becomes too great for the elektromagnetic forces to repell them, thus letting atoms collaps under the weight of all other atoms, fusing electrons and protons to create neutrons. You just made a neutron-star. Now it's the strong nuclear force creating resistance to further collapse, but just keep on adding mass and eventually even that force is outstronged by gravity, making further collapse possible. Now you made a black hole.[/quote'] Actually you are overcoming the degeneracy pressure. Electrons and neutrons are fermions and obey the Pauli exclusion principle. That's what prevents the initial collapse - you don't have a large enough force to put all of those particles in the same state. Link to comment Share on other sites More sharing options...
jsatan Posted November 8, 2004 Share Posted November 8, 2004 Gravity is the weakest of the forces. and then yoda, (I know off topic) Link to comment Share on other sites More sharing options...
SubJunk Posted November 8, 2004 Share Posted November 8, 2004 i could be wrong, but last i checked our current widely accepted theories don't explain exactly how gravity or magnetism really works. e.g. newton gives examples but not reasons. and Rootje it's Hawking sorry for being pedantic but one of the greatest men alive shouldn't have their names spelled incorrectly Link to comment Share on other sites More sharing options...
Spaceman Posted November 9, 2004 Share Posted November 9, 2004 '']And "permanent" magnets are not permanent. It takes a long time, but they will lose their magnetism eventually. show me the evidence to back this claim,subjunk as already said my point of view,and i find him quite interlectual Link to comment Share on other sites More sharing options...
Severian Posted November 11, 2004 Share Posted November 11, 2004 i could be wrong, but last i checked our current widely accepted theories don't explain exactly how gravity or magnetism really works. Why do you say this? Our theories explain how gravity and magnetism work very well. Magnetism for example is caused by the universe having a local U(1) symmetry. Why the universe has a local U(1) symmetry is of course not yet clear, but if one accepts that it has, electromagnetism is a natural consequence. Link to comment Share on other sites More sharing options...
jeheron Posted November 28, 2004 Share Posted November 28, 2004 In reply to explaining the force of gravity... we are still waiting for the Higgs Boson Link to comment Share on other sites More sharing options...
Severian Posted November 28, 2004 Share Posted November 28, 2004 The Higgs boson has nothing to do with gravity. Link to comment Share on other sites More sharing options...
jeheron Posted November 29, 2004 Share Posted November 29, 2004 The Higgs boson is a hypothesised particle which, if it exists, would give the mechanism by which particles acquire mass. Matter is made of molecules; molecules of atoms; atoms of a cloud of electrons about one-hundred-millionth of a centimetre and a nucleus about one-hundred-thousandth the size of the electron cloud. The nucleus is made of protons and neutrons. Each proton (or neutron) has about two thousand times the mass of an electron. We know a good deal about why the nucleus is so small. We do not know, however, how the particles get their masses. Why are the masses what they are? Why are the ratios of masses what they are? We can't be said to understand the constituents of matter if we don't have a satisfactory answer to this question. Peter Higgs has a model in which particle masses arise in a beautiful, but complex, progression. He starts with a particle that has only mass, and no other characteristics, such as charge, that distinguish particles from empty space. We can call his particle H. H interacts with other particles; for example if H is near an electron, there is a force between the two. H is of a class of particles called "bosons". We first attempt a more precise, but non-mathematical statement of the point of the model; then we give explanatory pictures. In the mathematics of quantum mechanics describing creation and annihilation of elementary particles, as observed at accelerators, particles at particular points arise from "fields" spread over space and time. Higgs found that parameters in the equations for the field associated with the particle H can be chosen in such a way that the lowest energy state of that field (empty space) is one with the field not zero. It is surprising that the field is not zero in empty space, but the result, not an obvious one, is: all particles that can interact with H gain mass from the interaction. Thus mathematics links the existence of H to a contribution to the mass of all particles with which H interacts. A picture that corresponds to the mathematics is of the lowest energy state, "empty" space, having a crown of H particles with no energy of their own. Other particles get their masses by interacting with this collection of zero-energy H particles. The mass (or inertia or resistance to change in motion) of a particle comes from its being "grabbed at" by Higgs particles when we try and move it. If particles no get their masses from interacting with the empty space Higgs field, then the Higgs particle must exist; but we can't be certain without finding the Higgs. We have other hints about the Higgs; for example, if it exists, it plays a role in "unifying" different forces. However, we believe that nature could contrive to get the results that would flow from the Higgs in other ways. In fact, proving the Higgs particle does not exist would be scientifically every bit as valuable as proving it does. These questions, the mechanisms by which particles get their masses, and the relationship amongs different forces of nature, are major ones and so basic to having an understanding of the constituents of matter and the forces among them, that it is hard to see how we can make significant progress in our understanding of the stuff of which the earth is made without answering them. By Mary and Ian Butterworth, Imperial College London, and Doris and Vigdor Teplitz, Southern Methodist University, Dallas, Texas, USA. http://www.phy.uct.ac.za/courses/phy400w/particle/higgs1.htm Link to comment Share on other sites More sharing options...
Severian Posted November 29, 2004 Share Posted November 29, 2004 Your article does not mention gravity. I repeat, the Higgs boson has nothing to do with gravity. The Higgs mecahnism is simply a mechanism for breaking the electroweak symmetry. As the article points out, breaking this electroweak symmetry with the Higgs mechanism, causes the fundamental particles to aquire mass (proportional to their coupling with the Higgs boson). But this is not relevant to gravity for two reasons: 1. Gravity does not care about mass. Mass is only in Newton's theory because the slow moving particle he observed have most of their energy as mass. Massless particles are still affected by gravity. 2. The masses provided by the Higgs boson are only for the fundamental particles. A large proportion of the masses of particle bound states (such as the proton) comes from QCD. So even without the Higgs mechanism, there would still be mass; just not at a fundamental level. Link to comment Share on other sites More sharing options...
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